The ability to use light to transmit information has been known for centuries. For example, the photophone uses modulated sunlight to transmit information, in that the brightness of a reflected beam of light observed at the receiver, varied based on audio-frequency variation in air pressure (e.g., sound wavers) which act upon the mirror. In this design, the transmitter has sunlight reflected off a surface of a over a thin mirror positioned at an end of a speaking tube, as words are spoken the mirror oscillates between convex and concave shapes, altering the amount of light reflected from its surface to the receiver. Another example of known communication techniques using light include Morse code in which the visible on/off switching (e.g., pulsing) of a light source is decoded by an observer to obtain the text information. Other techniques and implementations using modulated light to transmit information are known, however, in each of these techniques the modulation of the light source is perceptible by the human eye, which can enable the communicated data to be compromised.